Air-Assisted Marine Vehicles for Future Use in Transoceanic Transportation

2003 ◽  
Author(s):  
Konstantin I. Matveev
Keyword(s):  
Hydrodynamic Drag ◽  
Air Cavity ◽  
Technical Aspects ◽  
Research Opportunities ◽  
Marine Vehicles ◽  
Drag Ratio ◽  
Air Medium ◽  
The Way

The technical aspects of two types of advanced marine vehicles, Air Cavity Ship and Wing-In-Ground, are considered for future use in transoceanic transportation. Both concepts utilize the air medium to improve technical and economic characteristics of transportation means. The air is supplied under the bottom hull sections of the Air Cavity Ship, reducing the overall wetted surface and consequently hydrodynamic drag. A contact with water is completely eliminated in the case of the Wing-in-Ground, which moves above the water. This results in enhancing the lift-drag ratio in comparison with a flight in the open air. The principles, experience, and research opportunities on the way to make these concepts applicable for transportation are discussed.

Context

2020 ◽  
pp. 1-20
Author(s):  
Tom Bashford ◽  
Julian Gore-Booth ◽  
Jo James ◽  
Stephen Pickering ◽  
Becky Paris ◽  
...  
Keyword(s):  
Local Context ◽  
Technical Aspects ◽  
Low Resource Settings ◽  
Low Resource ◽  
Resource Setting ◽  
Low Resource Setting ◽  
Clinical Background ◽  
Developmental Principles ◽  
The Way

The chapter provides the reader with information on the non-clinical background to working as an anaesthetist in a low-resource setting. It concentrates on important concepts that should inform the way you practise and teach, rather than technical aspects of anaesthesia. Although technical aspects of delivering anaesthesia are usually uppermost in the minds of anaesthetists new to working in low-resource settings, it is often the case that adapting successfully to the local context proves the more challenging aspect. Topics covered include humanitarian and developmental principles, teaching anaesthesia, looking after your own health, being a good visitor, and how to adapt your practice.

An interface for ‘flat music’

2004 ◽  
Vol 9 (3) ◽  
pp. 243-250 ◽  
Author(s):  
CHRISTOPHER BAILEY
Keyword(s):  
Computer Music ◽  
Large Scale ◽  
Concert Hall ◽  
Technical Aspects ◽  
Specific Instance ◽  
Listening Experience ◽  
The Way ◽  
Musical Forms

Part of my listening experience has been a coming to terms with a certain set of musical forms that I call ‘flat’. Music in flat form means music that avoids obvious or dimensionally conjunct large-scale goals, points of arrival, ‘climaxes’, sectional boundaries, and the like, and therefore has proven difficult for many listeners. It has become clear to me that this music demands a different listening approach, one at odds with the way music is typically appreciated in the concert hall. This approach is one that composers of music in flat form can facilitate through today's computer-music resources. What I present here is a specific instance of such an approach: my composition Sand, a twenty-five-minute long work for computer-synthesised and processed sounds, was composed specifically to be experienced through a computer-music interface I built in the MAX/MSP environment. This paper explores what I mean by ‘flatness’, how I came to terms with it as a listener, and how this coming-to-terms spawned the idea and construction of the interface. I then discuss the interface itself, the process of interaction with the listener, and technical aspects of the software.

Ship Hull Drag Reduction Using Bottom Air Injection

2007 ◽  
Author(s):  
Ahmad Fakhraee ◽  
Manoucher Rad ◽  
Hamid Amini ◽  
Mehdi Rishehri
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Frictional Resistance ◽  
Air Injection ◽  
Hydrodynamic Resistance ◽  
Alternative Form ◽  
Hydrodynamic Characteristics ◽  
Air Cavity ◽  
Marine Vehicles ◽  
Wetted Surface Area

Air cavity ship concept has received some interest due to its potential on viscous resistance reduction for high speed craft. Air-cavity ships (ACS) are advanced marine vehicles that use air injection at the wetted hull surfaces to improve a vessel’s hydrodynamic characteristics. Air is supplied through nozzles under a profiled bottom to generate an air cavity beneath such a ship, so that a steady air layer separates a part of the bottom from contact with water, consequently reducing hydrodynamic resistance. Resistance tests were conducted with two forms: first of which was planning catamaran hull form, and second one was an alternative form with an air cavity injection under its bottom which was tested both without any air injection and with three different air injection ranges. Dead rise angle was fixed to 23 degree during both model tests. Frictional resistance was calculated from wetted surface area and compared with total resistance. It is clear from these results that improvements in high speed planning catamarans can be realized by using bottom air injection. Drag reduction achieved on these model is within 13–23 percent.

scholarly journals Lift-to-Drag Ratio of the Application of Hydrofoil With Variation Mounted Position on High-Speed Patrol Vessel

CFD letters ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1-9
Author(s):  
Muhammad Arif Budiyanto ◽  
Naufal Yudha Prawira ◽  
Haekal Dwiputra
Keyword(s):  
High Speed ◽  
High Performance ◽  
Hydrodynamic Performance ◽  
Comparison Result ◽  
Academic Literature ◽  
Marine Vehicles ◽  
Basic Model ◽  
Optimum Position ◽  
Drag Ratio ◽  
Lift To Drag Ratio

The hydrofoil is one of the hydrodynamic support technologies for marine vehicles that provide a high performance and are feasible to operate. The mounting position of hydrofoils on the hull is one of the keys to improving the hydrodynamic performance, where the existing academic literature to find the optimum position of hydrodynamic is still deficient. The objective of this study is to compare the mounting locations of hydrofoil in the horizontal axis in a high-speed patrol vessel. The comparison result is based on the computational fluid dynamics where the basic model was validated using experimental data. Three mounting location cases of hydrofoils were performed i.e. middle section, stern section, and behind the stern. The result shows that the optimal hydrofoil mounting position is after the transom. In this position, the value of the lift-to-drag ratio is higher by an average of 10% - 29% compared to other positions depending on the speed of the ship.

scholarly journals Numerical Investigation of High-Reynolds-Number Air-Ventilated Water Flow under Solid Body with Surface Geometry Variations

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 174
Author(s):  
Konstantin I. Matveev ◽  
Jeffrey M. Collins
Keyword(s):  
Stability Boundary ◽  
Practical Interest ◽  
The Body ◽  
Surface Geometry ◽  
Air Cavity ◽  
Operational Conditions ◽  
Marine Vehicles ◽  
Air Supply ◽  
High Reynolds ◽  
Air Cavities

Air-ventilated cavities formed under or around the hulls of marine vehicles can reduce water drag. Hull configurations with partial air ventilation where air cavities reattach to body surfaces are of special practical interest, since the required air supply rates to achieve significant drag reduction can be made rather low. However, formation and stability of such air cavities are sensitive to the hull geometry and operational conditions. In this study, an attempt is made to numerically simulate one setup with a partial air cavity that was previously tested experimentally at high Reynolds numbers, above 50 million. A computational fluid dynamics software Star-CCM+ has been employed for numerical modeling. Stable and unstable states of the air-cavity setup, characterized by long and collapsing air cavities, respectively, were modeled at two air supply rates near the stability boundary. Numerical results were similar to experimental data at the optimal water speed for the tested geometry, when a long air cavity was sustained at a minimal air supply rate. For water speeds that were substantially higher or lower than the optimal case, a stable cavity could not be maintained with small air supply rates for the given hull geometry. Numerical simulations demonstrated how alterations of the body surface could help sustain long air cavities across a broader speed range using air supply rates that were similar to the optimal case. These findings suggest that morphing hull surfaces can potentially be used for control of drag-reducing air cavities and expand the viable operating range for their application to marine vehicles.

scholarly journals Contemporary trends in the use of space in electroacoustic music

2008 ◽  
Vol 13 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Felipe Otondo
Keyword(s):  
Considerable Increase ◽  
Electroacoustic Music ◽  
Technical Aspects ◽  
Use Of Space ◽  
Spatial Design ◽  
Spatial Systems ◽  
Different Types ◽  
Channel Systems ◽  
The Way

AbstractThis paper describes a survey of contemporary approaches towards the use of spatial design in electroacoustic music, focusing on the type of spatial systems used by a sample of composers and the way they conceive the use of space in their music. Comparing the results with information gathered from seventeen articles by composers written on the topic in 1997, it is shown that composers nowadays are more used to working with different types of spatialisation systems than before. There is also a considerable increase in the use of surround 5.1 as well as four- and eight-channel systems and a decrease in the use of stereo. The compared results also show that, in general, composers nowadays seem to be less concerned with performance and interpretation issues as well as technical aspects of spatialisation. Further studies could consider a more detailed investigation of how the new spatialisation tools have shaped the aesthetical character of the music composed in recent years.

scholarly journals EDITIORIAL NOTE VOL 1, NO 1 (2011)

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Klaus Solberg Soilen
Keyword(s):  
Information Technology ◽  
End Users ◽  
Technical Equipment ◽  
Great Pleasure ◽  
Technical Aspects ◽  
Know How ◽  
Intelligence Studies ◽  
The Way

It is with great pleasure that we publish the first ten articles of JISIB. The articles represent a broad collection of topics from within the discipline of Intelligence Studies. There is a, we think, a balance in this issue between more managerial and more technical aspects of Intelligence Studies. In today’s world, intelligence problems are more often solved with the help of software and technical tools. It is no longer the case in organizations that managers work only with managerial aspects and technicians with technical aspects. Instead it has become a requirement that each group know a bit of both. Managers need to know how to operate software and new technical equipment and technicians need to know about the needs of end-users to be of value. This does not mean that professional specialties are about to disappear. It is more a sign that information technology is getting a tighter grip around the way we build successful organizations. Any study of intelligence with the aim to be relevant needs to reflect this.

scholarly journals Ukraińska mniejszość narodowa w Telewizji Polskiej. Analiza programów dla ukraińskiej mniejszości przed, podczas i po Euro¬majdanie na Ukrainie

2018 ◽  
pp. 23-38
Author(s):  
Tetyana Banytska
Keyword(s):  
Public Television ◽  
Television Programs ◽  
Technical Aspects ◽  
Civil Unrest ◽  
Diversity Methods ◽  
Public Media ◽  
Important Quality ◽  
Quality Issues ◽  
The Way

This article is an attempt to assess the quality of television programs targeted to Ukrainiannational minority in Poland. Public media in Poland have an obligation  of broadcasting programs for the minorities in their languages, which is imposed by the law on broadcasting. For the Ukrainian minority the Polish public television broadcasts three programs: „Przegląd ukraiński”, „Ukraińskie wieści” oraz „Telenowyny”. In this article the most important quality issues of these programs, such as duration of programs, subject diversity, methods of translation, technical aspects as well as the way of showing the civil unrest in Ukraine known as Euromaidan, are presented. An analysis was conducted within the timespan before, during and after the wave of demonstrations  in Ukraine (from 21 July 2013 to 22 June 2014).

Aotearoa New Zealand: keeping the virus at bay

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Spencer Lilley
Keyword(s):  
New Zealand ◽  
Design Methodology ◽  
Changing Environment ◽  
Content Type ◽  
Research Opportunities ◽  
Aotearoa New Zealand ◽  
Future Outcomes ◽  
The Impact ◽  
The Way

PurposeThis paper responds to an invitation from the Editor to write about how the COVID-19 virus has impacted on New Zealand and possible future outcomes, which are presented as three scenarios.Design/methodology/approachThis paper uses a scenario-based methodology to outline the implications of COVID-19 in New Zealand. Three different scenarios are presented for consideration.FindingsThere is a need for adaptability and flexibility in the way that New Zealand approaches how it recovers from the impact that COVID-19 has had. Specific challenges for libraries are to ensure that they can continue to deliver resources and services to their communities in a fast-changing environment.Research limitations/implicationsThere will be a substantial number of research opportunities in the years ahead to identify how libraries were able to contribute to recovery efforts.Originality/valueThis is a thought piece, delivered as scenarios. It only presents the views of the author.

Password-Less Authentication

2019 ◽  
pp. 190-212
Author(s):  
Rahul Singh Chowhan ◽  
Rohit Tanwar
Keyword(s):  
Great Benefit ◽  
Use Case ◽  
Unauthorized Access ◽  
Research Opportunities ◽  
Traditional System ◽  
The Past ◽  
Working Principle ◽  
User Friendly ◽  
Use Case Diagram ◽  
The Way

Over the years, passwords have been our safeguards by acting to prevent one's data from unauthorized access. With the advancement of technologies, the way we have been using passwords has changed and transformed into much secure yet more user friendly than they were ever been in the past. However, the vulnerabilities identified and observed in this traditional system has motivated industry and researchers to find some alternate where there is no threat like stealing, hacking, and cracking of password. This chapter discusses the major developed password-less authentication techniques in detail and also puts an effort to explain the in-depth details along with the working principle of each of the technique through a use-case diagram. It would be of great benefit and contribution to the callow trying to explore research opportunities in this area.

Sign in / Sign up

Export Citation Format

Share Document